Phenyl bromoacetate may be employed as alkylation reagent in the preparation of 2-(phenoxycarbonyl)methyl triazoles. It may be used in the synthesis of the A-ring of cylindrospermopsin and in the synthesis of 2-{2-[1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)ethylidene]hydrazinyl}-1,3-thiazolidin-4-one3, 2-{2-[1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)ethylidene]hydrazinyl}-3-methyl-1,3-thiazolidin-4-one3, 3-ethyl-2-{2-[1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)ethylidene]hydrazinyl}-1,3-thiazolidin-4-one3 and 2-{2-[1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)ethylidene] hydrazinyl}-3-phenyl-1,3-thiazolidin-4-one3.